The present invention relates to a conduction breaking device for breaking conduction between a pair of devices in an electric circuit by cutting a metal conductive body extending between the devices.
Electric circuits are provided with a conduction breaking device for breaking conduction between devices by being activated when malfunction occurs in a device in the electric circuit or a system on which the electric circuit is mounted. As one form thereof, a conduction breaking device has been proposed that forcibly cuts a metal conductive body located between devices by moving a blade with gas (see Japanese Patent Nos. 4228063 and 4344255, for example).
This type of conduction breaking device has a basic structure as illustrated in FIG. 16. A conduction breaking device C includes a metal conductive body 81 having a cuttable portion 81A, a cutting chamber 82, a gas generator 83, and a cutter block 84. The cutting chamber 82 and the gas generator 83 are arranged to sandwich the cuttable portion 81A in the thickness direction (the up-down direction as viewed in FIG. 16). The cutting chamber 82 has a rectangular opening 85, which faces the cuttable portion 81A, and a side of the opening 85 forms a cutting edge portion 86. An accommodating chamber 87 is formed between the cuttable portion 81A and the gas generator 83. The cutter block 84 is arranged in the accommodating chamber 87 to be movable in the thickness direction of the cuttable portion 81A.
When the gas generator 83 of the conduction breaking device C receives an activation signal, the gas generator 83 generates gas. The gas pushes the cutter block 84 toward the cutting chamber 82, so that the cuttable portion 81A is cut between the cutting edge portion 86 and the cutter block 84. Accordingly, the conduction between devices is broken.